In vacuum cleaners, vacuum cleaner filter bags are often used for filtering the sucked-in air. These vacuum cleaner filter bags comprise a bag wall of a filter material which filters out the dust and dirt particles contained in the sucked-in air, and a holding plate fixed at the bag wall to position the vacuum cleaner filter bag in the vacuum cleaner. At the apparatus, a mounting with which the holding plate can be engaged is often associated to the holding plate in the vacuum cleaner, whereby in turn the positioning of the vacuum cleaner filter bag in the vacuum cleaner is achieved. Via a connecting piece, the air to be filtered is usually directed into the interior of the filter bag through a passage opening in the holding plate and in the bag wall.
As a material for the holding plate, plastic is often used. Moreover, holding plates are known which consist of two different plastics and are manufactured in a two-component injection molding process. For example, DE 10 2007 040 417 describes a plastic holding plate with a closure flap, where the opening periphery is made of a softer plastic than the holding plate itself. Closure flaps are often used to close the passage opening in the bag wall and the holding plate when the vacuum cleaner is not in operation.
From DE 02 005 041 811, a holding plate with an elastomer seal injected to it is known. Such sealing lips are usually provided in the region of the passage opening of the holding plate and are to prevent dust from leaking from the vacuum cleaner filter bag by sealing the region between the inner periphery of the passage opening and the outer surface of a connecting piece of the vacuum cleaner. Such sealing lips are also known from DE 21 16 579, DE 10 2006 029059, or DE 10 2005 027 078. From DE 10 2007 057 171, a plastic seal with radially extending reinforcements is moreover known.
The holding plate is often connected with the bag wall of the vacuum cleaner filter bag by a material bond by means of ultrasonic welding. From DE 102 03 436, for example, a holding plate of cardboard is known which is coated with plastic permitting the welding of the holding plate to the bag wall. DE 20 2004 008 971 describes an ultrasonic welding connection between a plastic holding plate and a bag wall which at least partially consists of a thermoplastic filter material, wherein between the holding plate and the bag wall, a seal membrane of plastic material is moreover arranged. A similar solution with a rubbery-elastic layer is known from DE 10 2007 062 028. In both cases, the connection of the holding plate with the bag wall is complicated by the additional seal membrane or rubbery-elastic layer, respectively.
The connection of known holding plates with a sealing lip injected to them with the bag wall by means of ultrasonic welding often turns out to be problematic as the introduced ultrasonic energy can lead to damages of the holding plate, for example the sealing lip. To avoid this, the introduced energy is minimized, which, however, involves the disadvantage that the connection thus formed between the holding plate and the bag wall can be relatively easily released. In other words, the holding plate can be separated again from the bag wall after welding with a relatively low expenditure of force. In particular when the full vacuum cleaner filter bag is removed from the vacuum cleaner, there thus is a risk in that the connection between the holding plate and the bag wall is unintentionally released and thus dust escapes from the vacuum cleaner filter bag.